Separation of solute materials such as hydrocarbon oils produced from algae is somewhat difficult due to the relatively low concentrations of algal cells and solute materials that are generally present in a growth medium. Due to the amount of water present in the growth medium, a relatively large quantity of energy has to be applied to recover the solute material in sufficient quantity.
U.S. Patent Application Publication No. 2009/0163731 discloses a method in which a solute material derived from algae, i.e., triglycerides, can be treated to produce glycerin and biodiesel co-products and those products subsequently separated. The method includes the use of a Podbielniak extractor to separate the co-products, operating in a countercurrent flow regime.
International Publication No. WO 2010/096002 discloses isolating oil from an algae slurry containing the oil. The slurry is feed into a three phase centrifugal separator having a stack of separating discs in which the separator is operated under a force of at least 4500 G. An oil phase, a liquid phase, and a bio-organic phase are obtained as three separate phases. The process includes rupturing the cell walls of the algae to obtain the oil. The oil can be extracted by a solvent such as methanol, ethanol, or ethyl acetate.
Although improvements have been made in recovering desirable solute materials produced from algae, there nevertheless is plenty of room for even more improvement made to make it practical to isolate and recover such materials from algae. There can be significant need for enhanced efficiency of solute recovery. It may also be desirable to separate or extract solute material derived from algae, without having to rupture the cell walls of the algae and/or without significantly destroying algal cell viability.